Early Timely Treatment of Class III Malocclusion

Skeletal and dental effects of a new compliance-free appliance, the NET3 corrector, in management of skeletal Class III malocclusion compared to rapid maxillary expansion-facemask

OBJECTIVES

To examine retrospectively the short-term effects of a compliance-free skeletal Class III corrector (NET3-corrector) compared to rapid maxillary expansion-facemask (RME-FM).

MATERIAL AND METHODS

Records of 20 skeletal Class III patients treated with the NET3-corrector were compared to 20 patients treated with RME-FM, mean age: 11.14 ± 1.17 years and 11.14 ± 2.06, respectively. The NET3-corrector consisted of a hybrid-expander, a lower lingual arch, and a modified PowerScope spring. The RME-FM group received an RME-facemask combination. T2 records were collected when an overjet of at least 2 mm was achieved. Differences between two timepoints within groups and differences between groups were tested using paired samples t-test and independent samples t-test, respectively (P < .05 was considered statistically significant).

RESULTS

The treatment time was 10.5 months with NET3-corrector and 12 months with RME-FM. The NET3-corrector was well tolerated by patients and the Class III malocclusion was corrected in all patients in both groups. The overall maxillary skeletal change was greater with the NET3-corrector, with an additional 2° advancement at SNA (P < .001). Significant differences in maxillary incisor angulation were observed in the RME-FM group in comparison to NET3 (-0.37 ± 3.31 vs 4.96 ± 3.80; P < .001). The mandibular molars tipped significantly more distally in the NET3 group (7.3° more; P < .001).

CONCLUSIONS

The compliance-free tooth-bone-borne NET3-corrector, is effective in correcting Class III malocclusion with improved maxillary skeletal outcomes compared to RME-FM in the short term. These results need to be evaluated in the long term with a randomized sample.

Soft tissue changes associated with Class III orthopaedic treatment in growing patients: a systematic review and meta-analysis

INTRODUCTION

Achieving a harmonious soft tissue profile and enhancing facial appearance are key goals of early treatment for skeletal class III malocclusion.

AIM

To summarize the current evidence regarding the effects of Class III orthodontic treatment on facial soft tissues, and to compare various Class III orthodontic appliances.

METHODS

A comprehensive search was conducted up to July 2024, using seven databases, with no language restrictions. RCTs and controlled non-randomized studies were included in this systematic review. The GRADE framework was applied to evaluate the quality of evidence.

RESULTS

Thirty studies were included in this review, of which sixteen were appropriate for quantitative synthesis. The age range fell between 6.6 and 12.3 years. The FM/RME protocol resulted in a 1.58 mm increase in upper lip protrusion and a 4.73-degree decrease in the nasolabial angle compared to the control group. Chincup treatment led to a 2.13 mm increase in upper lip protrusion and a 2.63 mm decrease in lower lip protrusion compared to the control group. The pooled estimate demonstrated a significant increase of 1.82 mm in upper lip protrusion, a significant retrusion of 3.14 mm in the lower lip, and a backward movement of the chin by 4.8 mm in patients treated with miniplate-anchored orthopaedic facemask (FM/MP) compared to the untreated group. However, no significant difference was found between FM/RME and FM/MP, except for a noticeable decrease in the nasolabial angle in the FM/RME group. The analysis of FM/Alt-RAMEC versus FM/RME did not reveal any difference in soft tissue outcomes, except for the upper lip protrusion. The Alt-RAMEC group showed a more pronounced anterior movement of the upper lip by 0.67 mm compared to the RME group. The quality of evidence supporting these findings ranged from low to moderate.

CONCLUSIONS

There is low to moderate evidence suggesting that early treatment positively influences the soft tissues in Class III patients. However, these conclusions are based on a two-dimensional analysis of cephalometric images, which may not provide complete or accurate information. Therefore, more RCTs using comprehensive 3D analysis are needed to confirm these results.

REGISTRATION

PROSPERO ( CRD42024517924 ).

Biomechanical performance of ATOZ expander: Finite-element analysis

INTRODUCTION

Microimplant-assisted rapid palatal expansion appliances have been used for the treatment of orthodontic patients with maxillary deficiency. A new design named ATOZ (applicable from A to Z) was recently introduced to expand the scope of treatment in early permanent dentition. The objective of this study was to analyze the biomechanical performance of the ATOZ expander with various microimplants configurations using finite-element method.

METHODS

Nine ATOZ models were designed based on the number of microimplants configurations on the palate. For skeletal maturation, stage B midpalatal suture (MPS) maturation classification was chosen. A displacement along the sagittal axis, parallel to the MPS, of 0.15 mm was applied on each side of the device to simulate a 1 jackscrew turn of 0.3 mm.

RESULTS

Configurations 1, 2, 6, and 7 achieved a quasi-parallel skeletal movement with a uniform distribution of displacement in the maxilla. The highest posterior nasal spine to anterior nasal spine ratio of 95.95% was found with configuration 6, indicating an optimum quasi-parallel expansion. For configuration 2, microimplants 1 and 2 exhibited stresses of 619.18 MPa and 656.49 MPa, respectively, whereas microimplants 7 and 8 showed stresses of 609.64 MPa and 658.30 MPa, respectively. Maximum stress in zygomatic bone was 0.69 MPa. Higher stresses were more distributed in the zygomaticofrontal suture than in zygomaticotemporal and zygomaticomaxillary sutures.

CONCLUSIONS

In terms of posterior nasal spine to anterior nasal spine ratio, skeletal-to-dental ratio, and MPS deformation, ATOZ with configurations 1, 2, and 6 outperform other configurations, and thus, they can be recommended for correction of maxillary deficiency in patients with skeletal maturation of stage B or earlier.

Long-Term Predictive Modelling of the Craniofacial Complex Using Machine Learning on 2D Cephalometric Radiographs

OBJECTIVE

This study aimed to predict long-term growth-related changes in skeletal and dental relationships within the craniofacial complex using machine learning (ML) models.

MATERIALS AND METHODS

Cephalometric radiographs from 301 subjects, taken at pre-pubertal (T1, age 11) and post-pubertal stages (T2, age 18), were analysed. Three ML models-Lasso regression, Random Forest, and Support Vector Regression (SVR)-were trained on a subset of 240 subjects, while 61 subjects were used for testing. Model performance was evaluated using mean absolute error (MAE), intraclass correlation coefficients (ICCs), and clinical thresholds (2 mm or 2°).

RESULTS

MAEs for skeletal measurements ranged from 1.36° (maxilla to cranial base angle) to 4.12 mm (mandibular length), and for dental measurements from 1.26 mm (lower incisor position) to 5.40° (upper incisor inclination). ICCs indicated moderate to excellent agreement between actual and predicted values. The highest prediction accuracy within the 2 mm or 2° clinical thresholds was achieved for maxilla to cranial base angle (80%), lower incisor position (75%), and maxilla to mandible angle (70%). Pre-pubertal measurements and sex consistently emerged as the most important predictive factors.

CONCLUSIONS

ML models demonstrated the ability to predict post-pubertal values for maxilla to cranial base, mandible to cranial base, maxilla to mandible angles, upper and lower incisor positions, and upper face height with a clinically acceptable margin of 2 mm or 2°. Prediction accuracy was higher for skeletal relationships compared to dental relationships over the 8-year growth period. Pre-pubertal values of the measurements and sex emerged consistently as the most important predictors of the post-pubertal values.

Class III Correction With Reverse Twin Block-A Case Report

The orthodontic management of patients with Class III malocclusion poses numerous treatment challenges. Various removable, fixed, orthopedic, and myofunctional appliances have been recommended for its correction. The Reverse Twin Block is a removable appliance which has been used for the early management of such cases. A 10-year-old female with no significant medical and family history presented with the chief complaint of forward placement of lower front teeth on biting. Extraoral examination revealed a mesoprosopic face, a prominent lower lip, and a shallow mentolabial sulcus. Facial profile was straight at rest and concave at maximum intercuspation. Intraoral examination revealed a Class III incisor relationship with premature contact between 21 and 31, causing a forward path of closure of the mandible. The patient had a reverse overjet of 2 mm, an overbite of 5 mm, and a bilateral Super-class I molar relationship at maximum intercuspation. Lateral cephalogram analysis revealed a mild skeletal class III denture base (ANB = 0°, Wits = -4 mm) due to a prognathic mandible (SNB = 82°). The treatment objectives included elimination of the premature contact, establishment of a positive overjet, and improvement of the facial profile. A Reverse Twin Block appliance was planned and prescribed for full-time wear for 8 months. At the end of treatment, the patient had a Class I incisor relationship, straight facial profile, Class I molar relationship on the left side, and Super-class I molar relationship on the right side. The Reverse Twin Block is a simple and well-tolerated appliance that can effectively correct developing Class III malocclusion in carefully selected cases.

Treatment of maxillary hypoplasia with bone anchored maxillary protraction (BAMP) - A case report

Early diagnosis and treatment is known to be beneficial in Class III malocclusions secondary to maxillary hypoplasia. However, success of treatment largely depends on the patient's compliance and thus, appropriate choice of treatment, appliance and the age for interception plays an important role. Bone anchored maxillary protraction is one such approach presented in this case report for a 13 years old boy who reported with the chief complaint of lower front teeth visibility during speech and smiling. On examination his molars were in Angle's Class III relation, anterior crossbite and deep bite with unerupted maxillary canines. Orthodontic treatment was begun for deep bite correction and for creating space for the maxillary canines, followed by surgical intervention for placement of bone anchored miniplates. Protraction was done for 14 months and the total treatment time was 20 months. Improvement in the patient's profile, aesthetics and function was achieved with well aligned arches.

Airway dimensional changes following bone anchored maxillary protraction: a systematic review

BACKGROUND

The introduction of skeletal anchorage utilized for maxillary protraction with a face mask or class III elastics has been developed for the management of class III malocclusions with minimal dental effect. The objective of the present review was to evaluate the current evidence regarding airway dimensional changes following bone-anchored maxillary protraction. A search was conducted by two authors (S.A & B.A) in the following databases: MEDLINE via PubMed, Cochrane Library, Web of Science, Scopus, Google Scholar and Open Grey; besides a hand search in references of selected articles and developing a search alert in electronic databases. Selection criteria comprised randomized as well as prospective clinical trials evaluating airway dimensional changes following bone-anchored maxillary protraction. Relevant data were extracted after studies retrieval and selection. The risk of bias was thereafter evaluated using the revised RoB 2 tool for randomized clinical trials and the ROBINS-I tool was used for non-randomized clinical trials. The quality of studies was assessed using the modified Jadad score. After examining (eligibility) full-text articles, four clinical trials were ultimately included. These studies evaluated the airway dimensional changes, following bone-anchored maxillary protraction in comparison to different control study groups. Based on the available evidence, all the bone-anchored maxillary protraction devices used in the eligible studies in the present systematic review resulted in an improvement in the airway dimensions. However, due to the few numbers of studies available and the guarded evidence due to the low quality of evidence of three out of four included articles, there is no strong evidence to support a significant increase in the airway dimensions following bone-anchored maxillary protraction. Therefore, there is a need for more randomized controlled clinical trials with similar bone-anchored protraction devices and similar assessment methods for more valid comparisons, excluding any confounding factors, on airway dimensional changes.

Temporomandibular joint articular disc position and shape in skeletal Class III

OBJECTIVE

To compare the position and shape of the temporomandibular joint (TMJ) articular disc among the sagittal and vertical skeletal patterns in Angle Class III, Class III subdivision malocclusion and normal occlusion. The null hypothesis was that there was no difference in disc position and shape in different (1) malocclusions and (2) skeletal patterns.

METHODS

This cross-sectional observational study evaluated 105 patients divided into 3 groups: Class III (33, 9.39 ± 1.96 years), Class III subdivision (45, 9.51 ± 1.59 years) and a normal occlusion (27, 10.24 ± 0.87 years) was included as healthy control. Severity of the maxilla-mandibular anteroposterior discrepancy and vertical facial pattern were determined using 2D cephalometry, and the position and shape of the articular discs were evaluated in magnetic resonance images. Statistical parametric and non-parametric tests and Kappa analysis for intra-observer and inter-observer assessment were used (p ≤ .05).

RESULTS

Significant between-group differences were found in articular disc position. In the normal occlusion group, all the articular discs were well positioned. In Class III and Class III subdivision, the discs were displaced in 30.3% and 12.2% of the TMJs, respectively. Sagittal and vertical skeletal patterns did not affect the findings significantly. The Class III subdivision malocclusion group is probably different from the other groups, showing 97.7% of biconcave discs in both TMJs.

CONCLUSION

The longitudinal follow-up of this sample becomes relevant as the two groups with malocclusion in the pre-peak phase of pubertal growth showed differences in the prevalence of displacement and form of the articular disc, with no association with their vertical facial characteristics.

Very early orthodontic treatment: when, why and how?

Introduction:

Several orthodontic problems should already be treated at an early age to prevent the necessity of future complex and expensive procedures. Scientific evidence suggests that posterior crossbites, mild to moderate Class III, as well as certain Class II malocclusions, open bites and arch length discrepancies can benefit from simple, but efficient interceptive therapy.

Objective:

To summarize the existing evidence-based literature on early orthodontic treatment, and to illustrate its application and effectiveness by showcasing multiple clinical examples.

Conclusion:

Early short-term interceptive orthodontic treatment with simple appliances, in the deciduous or early mixed dentition phase, can efficiently correct certain malocclusions and help to either reduce the complexity or even avoid the necessity of complex and expensive procedures during puberty. For certain patients with significant arch length discrepancy the concept of serial extractions should be part of the orthodontic armamentarium.

Treatment of Class III Malocclusion and Anterior Crossbite with Aligners: A Case Report

The article describes the orthodontically treated case of a 25-year-old patient with skeletal and dental class III malocclusion, anterior crossbite, which caused functional and aesthetic problems, occlusal trauma, and incisor wear. Treatment with transparent aligners was proposed to meet the patient's needs, using the sequential distalization protocol. While sequential distalization is well documented for class II malocclusion treatment in maxillary arch teeth, further investigations are necessary for class III malocclusions. In fact, lower teeth movements are more complex due to mandibular bone density and the presence of the third molars, which are often extracted to perform distalization. In addition, the use of intermaxillary elastics helps control the proclination of the anterior teeth as a reaction to distalizing forces. At the end of the treatment, the patient reached molar and canine class I and positive overjet and overbite. The inclination of lower incisors and the interincisal angle have improved, resulting in aesthetic and functional enhancement.

Successful 2 phase treatment of growing skeletal Class III malocclusion based upon cephalometric prognostic factor: A case report

Early treatment of Class III malocclusion provides an improvement in facial appearance and corrects the reverse bite. Orthopedic protraction of maxilla is considered best approach in growing Class III patients with maxillary deficiency. Present case report describes the management of a growing 10-year-old boy with skeletal Class III malocclusion using facemask therapy (Phase 1) followed by fixed orthodontic treatment (Phase 2) based upon cephalometric prognostic findings of growth treatment response vector (GTRV). With the successful orthopedic phase of maxillary protraction with facemask therapy for 7 months of period, a significant improvement in profile had been achieved along with the correction in reverse overjet. This was followed by retention with chin cup therapy for a period of 20 months. After a period of 20 months retention, a fixed orthodontic treatment was started with the objective to achieve stable functional occlusion. After 11 months of treatment with fixed appliance therapy a stable functional occlusion was achieved. The patient was placed on Hawleys retainer in maxillary arch and bonded fixed spiral wire (FSW) retainer in mandibular arch. Successful management of growing Class III patient was done using facemask and fixed orthodontic therapy based upon cephalometric prognostic findings of growth treatment response vector (GTRV).

Early timely orthodontic treatment: Treatment of unerupted maxillary laterals

There is no universal agreement as to which type of orthodontic or orthopedic treatment deserves early intervention. In addition, there is a need for more information as to which treatments are the most effective and less costly if they are initiated timely in the mixed dentition. Early timely treatment may benefit young patients with a maxillary transverse deficiency with or without a posterior crossbite that requires maxillary expansion. It may also be indicated in children with anteroposterior jaw discrepancy that requires chin cup or maxillary protraction. In this paper, the authors will focus on early maxillary expansion to facilitate the eruption of maxillary laterals. In specific, the authors will present a contemporary protocol using a bonded maxillary expander as anchorage for treatment of unerupted maxillary laterals. The use of this protocol was illustrated with two case reports to enable clinicians to routinely achieve a beautiful smile on a young patient by timely alignment of the maxillary incisors.

Importance of orthodontic intervention of the Class III malocclusion in mixed dentition

INTRODUCTION

Supervising the development of occlusion, managing problems during the transition from mixed to permanent dentition, as well as controlling environmental factors that contribute to establishing malocclusion, are important actions to achieve a Class I occlusion with facial balance. Among these problems, the malocclusions associated with dysfunctions such as mouth breathing or obstructive sleep apnea syndrome (OSAS), atypical swallowing and abnormal tongue position, open bites, crossbites and maxillomandibular discrepancies, and especially the Class III malocclusion can be listed.

OBJECTIVE

The purpose of this article is to present and discuss the main aspects relevant to the benefits of performing the treatment of Class III malocclusion in patients with growth.

Comparison of two protocols for early treatment of dentoskeletal Class III malocclusion: Modified SEC III versus RME/FM

OBJECTIVE

To compare the short-term cephalometric outcomes of the protocols modified splints, Class III elastics, chincup (SEC III) and rapid maxillary expansion and facial mask (RME/FM) for the early treatment of growing subjects with Class III dentoskeletal malocclusion.

SETTINGS AND SAMPLE POPULATION

This retrospective observational study included 20 patients (11 males, nine females) treated with the modified SEC III protocol and 31 patients (16 males, 15 females) treated with the RME/FM one. The sample was evaluated before (T1, mean age 7.9 ± 1.0 years) and at the end of treatment (T2, mean age 9.0 ± 1.0 years). Statistical comparisons between the two groups were performed with independent sample t tests.

RESULTS

Both the modified SEC III and the RME/FM sample groups showed significantly favourable effects in terms of maxillary advancement (SNA +1.3° and +1.5°, respectively), control of mandibular projection (SNB -0.5° and -0.8°, respectively), and intermaxillary relationships (ANB +1.8° and +2.3°, respectively; Wits +3.4 and +1.9 mm, respectively). The modified SEC III group showed a statistically significant greater control in the intermaxillary divergency considering the SN to Pal. Pl. (P < 0.006) and Pal. Pl. to Mand. Pl. angle (P < 0.002) with a difference of 2.3 mm between the two groups.

LIMITATIONS

The main limitations of this study are its retrospective nature and the short-term outcomes.

CONCLUSION

Early treatment of growing patients with dentoskeletal Class III disharmonies is efficient using either modified SEC III or RME/FM protocols. However, a higher vertical control is achieved with the modified SEC III.

Maxillary dento-skeletal outcomes after orthopedic forward (class III) and backward (class II) traction in growing subjects

BACKGROUND

This retrospective study investigated the treatment effects produced by two orthopedic appliances, an extraoral orthopedic traction on Stephenson plate (SP) in skeletal Class II malocclusion and Delaire Facial Mask (FM) in skeletal Class III malocclusion.

METHODS

FM Group comprised 25 patients (13 males; 12 females, mean age 9.3 years, CS 1-2) undergoing Delaire Facial Mask therapy (mean treatment duration 1.5 years ± 1.2, 700-800 gr per side). SP Group comprised 24 patients (9 males; 15 females, mean age 10.5 years ± 1.9, CS 1-3) treated with extraoral orthopedic traction on Stephenson plate (mean treatment duration 1.6 years ± 0.8, 700-900 gr per side). For all subjects lateral cephalograms before (T0) and after (T1) therapy were obtained and traced. Descriptive statistics, t-test and Shapiro-Wilks test were calculated for each variable.

RESULTS

A mesial movement of the maxillary bone of 2.4 mm in the FM group and a distal movement in the PS group (0.4 mm) was found. SNA° was reduced 1.4° after SP and increased 0.7° after FM. The overjet decreased by 4 mm after SP, while it grew after FM by 2.4 mm, as well as molars relationships (4.5 vs. 0.8 mm).

CONCLUSIONS

Facemask induced greater skeletal movements than extraoral traction on Stephenson plate. PS produced a limited downward movement of the whole maxilla together with notable incisors and molars back corrections. Based on our results, it could be speculated that orthopedic mesial traction of maxillary bone may result easier than the distal movement.

Serum DHEA-S levels could be used as a comparable diagnostic test to assess the pubertal growth spurt in dentofacial orthopedics

Background

Pubertal growth spurt assessment guides the timing of intervention for correcting the skeletal discrepancies in dentofacial orthopedics. Serum hormones are being studied for the skeletal age assessment to avoid unnecessary radiographic exposure. The present study is to evaluate the relationship of serum hormones dehydroepiandrosterone-sulfate (DHEA-S), insulin-like growth factor (IGF-1), and cervical vertebral stages (CS stages) in the skeletal age assessment of orthodontics patients around the circumpubertal age.

Methods

A total of ninety subjects with age ranging from 7 to 21 years were selected and divided into two groups based on the sex (45 males, 45 females). They were further distributed in each group based on the six CS stages determined from the lateral cephalogram. Blood samples from each subject were collected to evaluate the serum DHEA-S and IGF-1 levels by using the enzyme-linked immunosorbent assay (ELISA). Collected data were analyzed in SPSS software with a test of normalcy, unpaired t test, and one-way analysis of variance (ANOVA) followed by the least significant difference (LSD) post hoc comparison test and univariate regression analysis.

Results

The highest mean serum hormone levels were found in CS 4 in group A (male) and CS 3 in group B (female). ANOVA results showed that there was a significant difference in the serum hormone levels among the different CS stages in both the groups for both the hormones. Statistically, a significant difference was found between each CS stages for both the hormones except in the DHEA-S levels between CS 5 and CS 6.

Conclusions

The mean serum DHEA-S levels followed a typical pattern from the CS 1 till CS 6 which was comparable and similar to the mean serum IGF-1 levels in respect to CS stages. Thus, serum DHEA-S levels could be used as a possible diagnostic test for the assessment of the skeletal pubertal growth spurt in dentofacial orthopedics.

A simplified de novo approach for vector control in facemask therapy

One of the most common clinical challenges encountered with facemask therapy for early correction of skeletal Class III malocclusions is the delivery of appropriate direction of force for effecting the pure translation of maxilla. This technical note describes a novel method involving the use of Begg's auxiliary for achieving efficient and predictable delivery of protraction forces. With this modified assembly, effective vector control for facemask can be achieved without the need to remove the bonded Hyrax assembly. This chairside modification is an effective and invaluable method for predictable force delivery in facemask therapy.

Direct Anterior Tracks: Early and Functional Management of Class III Malocclusions-Case Report and Literature Review

The prevalence of class III malocclusion ranged from 0 to 26% in different populations. Many types of treatments have been described in dental literature. The results of early treatment have been positive. The purpose of this report is to describe the case of a four-year-old patient with class III malocclusion who received an innovative treatment using direct anterior tracks. This therapy efficiently obtained immediate improvement of profile and occlusal relationships.

Stress on facial skin of class III subjects during maxillary protraction: a finite element analysis

BACKGROUND

Maxillary protraction with facemask (FM) is an orthopedic approach for treatment of Class III growing patients. Aim of the present investigation was to analyze tension loads produced by two different facial mask (FM) designs on facial skin of subject with skeletal Class III.

METHODS

A three-dimensional (3D) geometry of Delaire and Petit FM models were reconstructed from the original Computer Aided Design (CAD) 3D prototype using software package (ANSYS 5.7). A traction load of 9.8 N inclined of 30° to the occlusal plane was applied combining analytical FM models with a 3D facial model. Resulting stresses and deformations on the skin layer were tested through the von Mises yield criterion.

RESULTS

Overall tensions were mostly developed on the chin area, while lower stresses were observed on forehead area for both FM designs. When Delaire FM model was tested, maximum stresses were observed on the upper border of the chin cup corresponding to the inferior lip and to marginal gingiva of lower incisors. After Petit FM application, maximum stresses were more extensively localized at the level of both upper border and central area of the chin. Stresses measured on the chin area were significantly higher with Petit FM when compared with Delaire FM (44 KPa versus 29 KPa, respectively).

CONCLUSIONS

Delaire FM determined lower stresses and tensile tensions than Petit FM model. Highest tensions were observed at the level of chin cup area for both Delaire and Petit FM. Stresses following Delaire FM application were mostly observed on the upper border of the chin cup, while Petit FM determined stresses more extensively distributed to the central area of the chin.

Skeletal Class III correction in permanent dentition using reverse twin block appliance and fixed mechanotherapy

The orthodontic management of patients with Class III malocclusion poses numerous prognostic and treatment challenges to the clinician. Various removable, orthopaedic, myofunctional and fixed appliances have been recommended for the correction of Class III malocclusion. The Reverse Twin Block (RTB) is a simple and well tolerated appliance which has often been used for the early management of such cases in mixed dentition. Cases reporting use of RTB in permanent dentition are however, limited. This article presents an insight into the encouraging results of reverse twin block (RTB) appliance used in conjunction with fixed mechanotherapy for the successful treatment of a 12-year-old patient presenting with skeletal Class III malocclusion and a concave facial profile. The RTB appliance helped establish a favourable environment for unrestricted maxillary growth, at the same time redirecting the mandibular growth to a clockwise direction and correcting the incisal relationship. The favourable treatment outcome and long-term stability achieved substantiates the feasibility of RTB appliance in mild to moderate skeletal Class III malocclusions in permanent dentition cases.

Facemask performance during maxillary protraction: a finite element analysis (FEA) evaluation of load and stress distribution on Delaire facemask

BACKGROUND

To evaluate load and stress distribution on Delaire facemask (FM) during maxillary protraction in class III growing patients by means of finite element analysis (FEA). A three-dimensional geometry of a Delaire FM was reconstructed from the original CAD 3D prototype, using software package (ANSYS 5.7). FM presented forehead and chin supports and stainless steel framework characterized by two lateral vertical bars connected to a crossbar with two pawls for elastic attachment. Two traction intensities (7.8 and 9.8 N) were applied on the FM pawls along three different downward inclined directions with respect to the occlusal plane (0°, 30°, or 50°, respectively). Resulting stresses and deformations were then tested through the von Mises yield criterion in order to underline the FM wear performance.

RESULTS

The analysis showed that higher stresses and deformations are mostly related to axial forces of 9.8 N rather than 7.8 N. Stresses also progressively increased with increasing downward force inclinations (0°, 30°, and 50° with respect to the occlusal plane). The overall tensions were inferior to the limit of the elastic behavior (yield point) characterizing the material they are applied on. Thus, the FM structure absorbed the load applied with an elastic deformation of the lateral and horizontal bars.

CONCLUSIONS

Resulting stresses and deformations were directly proportional to protraction load amounts and to increasing downward inclination of forces. In all tested conditions, protraction forces were not able to determine plastic deformation on FM structure compromising its performance and efficiency.

Guiding the Child's Teeth with Class III Dental Malocclusion into Correct Occlusion: A Clinician's Parenting

Pediatric dentists are often the first ones to be consulted for the presence of an anterior cross bite in the primary dentition. The condition requires an early interception to avoid progressive dentoalveolar and skeletal changes. The management, however, poses unique challenges in terms of young age of the child, correct choice of appliance and unpredictability of the response to treatment due to inability to ascertain the inherent growth potential. It is very important therefore for the specialist, to be able to recognize the early signs of a developing class III malocclusion tendency and also know the basic details of successful management of such cases. The following article describes the appropriateness of appliance choice for a case of incisor cross bite in primary dentition using different appliances based on their varied clinical presentations.

Effects of Combined Bonded Maxillary Expansion and Face Mask on Dental Arch Length in Patients with Skeletal Class III Malocclusions

OBJECTIVE

To evaluate the effects of combined rapid maxillary expansion (RME) and face mask (FM) therapy during the mixed dentition period on the dental arch length in patients with skeletal Class III malocclusion.

STUDY DESIGN

We evaluated pre- and post-treatment orthodontic models of 52 patients (25 girls, 27 boys) aged 8-12 years with skeletal Class III malocclusion(ANB<0) accompanied by maxillary transverse deficiency and retrognatism treated by bonded RME-FM therapy for a mean duration of 8 months. Palatal rugae, the cusp tips of permanent first molars, deciduous molars/permanent premolars, deciduous canines and the incisal edges of permanent central incisors were marked on orthodontic models, which were then photocopied. Inter-molar, inter-premolar and inter-canine widths; the arch length; the arch depth and molar and incisor sagittal movements were measured on these photocopies. Statistical comparisons were made using paired t-tests.

RESULTS

Inter-molar, inter-premolar and inter-canine widths and the arch length showed significant increases after treatment, while the arch depth showed a significant decrease (p<0.001 for all).

CONCLUSIONS

With the study limitations, our results suggest that combined RME-FM therapy increases the arch length in the mixed dentition of patients with skeletal Class III malocclusion.

Treatment of Class III with Facemask Therapy

Class III malocclusion is one of the most difficult problems to treat in the mixed dentition. It has a multifactorial etiology involving both genetic and environmental causes. The dental and skeletal effects of maxillary protraction with a facemask are well documented in several studies. Although treatment in the late mixed or early permanent dentition can be successful, results are generally better in the deciduous or early mixed dentition. The following case shows early treatment of a young patient with severe sagittal and transverse discrepancy of the maxilla and mandible, using a facemask.

Management of skeletal Class III malocclusion with unilateral crossbite on a growing patient using facemask-bonded rapid palatal expander and fixed appliances

Facemask (FM) and bonded rapid palatal expander (RPE) are part of growth modification treatments for correcting skeletal Class III pattern with retrognathic maxilla. This orthopaedic treatment is usually preceded by fixed appliances to achieve aesthetic dental alignment and improve interdigitation. This case report reviews treatment of Class III malocclusion with unilateral crossbite in a 12-year-old boy using FM and bonded RPE, followed by fixed appliances. Choice of FM and bonded RPE was in line with indication which was mild Class III malocclusion with retrognathic maxilla. Execution of treatment was made considering treatment biomechanics and patient cooperation. This orthopaedic treatment was followed by orthodontic treatment specifically aimed to correct unilateral crossbite, canine relationship yet to reach Class I, lower midline shift, as well as unintended dental consequences of using bonded RPE, namely posterior open bite and deepening curve of spee. Posttreatment facial profile and smile are more esthetic. Occlusion is significantly improved both functionally and aesthetically.

Maxillary canine-first premolar bilateral transposition in a Class III patient: A case report

Tooth transposition is a rare dental anomaly that often represents a challenge for the clinician. The case of a girl with skeletal Class III malocclusion and concomitant maxillary canine-first premolar bilateral transposition, followed from 7 to 17 years of age, is presented. After a first phase of treatment aimed at resolving the Class III malocclusion, the transposition was maintained and the case finalized with a multibracket appliance.

Bonded versus banded rapid palatal expander followed by facial mask therapy: analysis on digital dental casts

OBJECTIVES

To compare the dental effects produced by a bonded versus a banded expander combined with facial mask (FM) in patients with Class III malocclusion by means of digital dental casts.

MATERIALS AND METHODS

Two groups of patients with Class III malocclusion and maxillary transverse deficiency in the deciduous or early mixed dentition were selected. The first group consisted of 25 subjects (12 females; 13 males) with a mean age of 7.4 years (SD 1.2 years) treated with a bonded expander and FM. The second group consisted of 25 subjects (13 females; 12 males) with a mean age of 8.1 years (SD 1.3 years) treated with a banded expander and FM. For each subject of the two groups, initial (pre-treatment, T1) and final (post-treatment, T2) dental casts were taken and scanned. Maxillary digital models of T1 and T2 were superimposed on the palatal rugae in order to analyse the maxillary anchorage loss. Significant between-group differences were tested with independent sample t-test (P < 0.05).

RESULTS

No statistical differences were found for any of the variables observed.

CONCLUSION

Orthopaedic treatment of Class III malocclusion with either a bonded or a banded expander and FM during the deciduous or early mixed dentition induced a significant expansion of the maxillary arch and a slight mesialization of the posterior anchoring teeth with no difference between the two intraoral appliance designs.

Class III treatment using facial mask: stability after 10 years

Early Class III malocclusion treatment may not have long-term stability due to mandibular growth. Although some features of this malocclusion point to a better prognosis, it is practically impossible for the orthodontist to foresee cases that require new intervention. Many patients need retreatment, whether compensatory or orthodontic-surgical. The present study reports the case of a Class III patient treated at the end of the mixed dentition with the use of a face mask followed by conventional fixed appliances. The case remains stable 10 years after treatment completion. It was presented to the Brazilian Board of Orthodontics and Dentofacial Orthopedics (BBO) as a requirement for the title of certified by the BBO.

Prediction of Class III treatment outcomes through orthodontic data mining

OBJECTIVE

To determine whether it is possible to predict Class III treatment outcomes on the basis of a model derived from a combination of computational analyses derived from complexity science, such as fuzzy clustering repartition and network analysis.

METHODS

Cephalometric data of 54 Class III patients (32 females, 22 males) taken before (T1, mean age 8.2 ± 1.6 years) and after (T2, mean age 14.6 ± 1.8 years) early rapid maxillary expansion and facemask therapy followed by fixed appliances were analysed. Patients were classified at T1 on the basis of high membership grade into three main dentoskeletal fuzzy cluster phenotypes: hyperdivergent (HD), hypermandibular (HM), and balanced (Bal) phenotypes. The prevalence rate of successful and unsuccessful cases at T2 was calculated for the three clusters and compared by means of Fisher's exact test corrected for multiple testing (Holm-Bonferroni method).

RESULTS

Unsuccessful cases were 9 out of 54 patients (16.7%). Once patients were framed into their cluster membership, the individualized pre-treatment prediction of unsuccessful cases was largely differentiated: HD and HM patients showed a significantly greater prevalence rate of unsuccessful cases than Bal patients (0% in Bal cluster, 28.6% in HM cluster, and 33.3% in HD cluster). Network analysis captured some noticeable interdependencies of Class III patients, showing a more connected interactive structure of cephalometric data sets in HM and HD patients compared with Bal patients. The results were confirmed after minimizing the geometrical connections between cephalometric variables in the model.

CONCLUSIONS

Fuzzy clustering repartition can be usefully used to estimate an individualized risk of unsuccessful treatment outcome in Class III patients.

Two-phase orthodontic treatment of a complex malocclusion: giving up efficiency in favor of effectiveness, quality of life, and functional rehabilitation?

The interceptive orthodontic treatment of patients with complex dentofacial abnormalities is frequently inefficient and produces less than ideal outcomes. Therefore, postponing therapy to a single-phase surgical-orthodontic approach might be considered a reasonable option. However, other relevant aspects of the patient's quality of life, such as possible psychosocial problems and functional impairments, should also be considered before deciding whether to intercept a severe dentofacial malocclusion while the patient is still growing, or wait and treat later. This case report describes the nonsurgical treatment of a young patient with a severe Class III open-bite malocclusion associated with a cervical cystic lymphangioma. Despite the poor interceptive therapy prognosis, a 2-phase approach was effective. A reflection about giving up efficiency in favor of effectiveness, functional rehabilitation, and the patient's quality of life is included.

Dentofacial effects of a modified tandem traction bow appliance

The aim of this study was to evaluate the dentofacial effects of a modified tandem traction bow appliance (modified TTBA) in skeletal Class III subjects, and the effect of age on treatment response. The material consisted of the pre-treatment/pre-observation and post-treatment/post-observation lateral cephalograms and hand-wrist films of 45 children with skeletal and dental Class III malocclusions. Thirty patients were treated with a modified TTBA. Two treatment groups of 15 patients each were formed: an early (nine girls, six boys; mean skeletal age: 8.18 ± 0.50 years) and a late treatment (5 girls, 10 boys; mean skeletal age: 11.75 ± 1.00 years) group. The remaining 15 children (5 girls, 10 boys; mean skeletal age: 7.90 ± 0.62 years) were observed without treatment for 8 months and served as a control for the early treatment group. Wilcoxon and Mann-Whitney U-tests were used for statistical analysis. Significant forward maxillary movement was determined in both treatment groups (P < 0.01) while the decrease in SNB was significantly greater in the early treatment group compared with the control (P < 0.01). Upper molar tipping and sagittal displacement of point A (point A-T, N(⊥)FH-A) was found to be significantly greater in the late treatment group compared with the early treatment group (P < 0.05). In both treatment groups, dental and skeletal correction of the Class III malocclusion was achieved.

Acceptability of adolescents' occlusion in Finnish municipal health centres with differing timing of orthodontic treatment

The objective of the study was to compare the acceptability of occlusion among orthodontically treated and untreated adolescents in eight Finnish municipal health centres applying different timing of treatment. A random sample of 16- and 18-year olds (n = 2325) living in these municipalities was invited for a clinical examination, and 1109 adolescents participated. Two calibrated orthodontists blindly examined the participants for the acceptability of occlusion with the Occlusal Morphology and Function Index. The history of orthodontic treatment was elicited by questionnaire. The impact of the history and timing of treatment on the acceptability of occlusion was analysed with logistic regression analysis. The history of orthodontic treatment decreased the odds for acceptability of morphology [odds ratio (OR) = 0.719, 95 per cent confidence limit (CL), P = 0.016] and acceptability of function (OR = 0.724, 95 per cent CL, P = 0.018). The early timing of treatment increased the odds for acceptability of morphology (OR = 1.370, 95 per cent CL, P = 0.042) and of function (OR = 1.420, 95 per cent CL, P = 0.023). No substantial differences were observed in the acceptability of occlusion between the early and late timing health centres. However, the proportion of subjects with acceptable occlusion was slightly higher in the early than in the late timing group. These findings suggest that when examining the effect of timing on treatment outcome, factors other than acceptability of occlusion should be concomitantly evaluated. Consequently, in this context, the duration and cost of treatment need to be investigated.

Long-Term Outcomes of Class III Treatment with Mandibular Cervical Headgear Followed by Fixed Appliances

Objective: To evaluate the stability of the outcomes of mandibular cervical headgear (MCH) and fixed appliance–treated Class III patients at a long-term posttreatment (5 years) observation, compared with well-matched untreated Class III controls, following a previous report on the short-term outcomes of this protocol.

Materials and Methods: The treated group consisted of 20 patients with dentoskeletal Class III malocclusions treated with a two-phase protocol consisting of MCH and fixed appliances, while the control group comprised 18 untreated subjects with similar dentoskeletal Class III malocclusion. Lateral cephalograms of both patients and controls were analyzed at two time points: posttreatment (PT), after two-phase treatment; and long term (LT). All patients were at a postpubertal stage of skeletal maturity at PT, and they showed CS6 at LT, thus revealing completion of pubertal craniofacial growth.

Results: In the long term, the treatment group showed significantly smaller values for mandibular length (Co-Gn), SNB angle, maxillomandibular differential, and molar relation. When compared with the controls, the treated patients exhibited also greater values for ANB angle, Wits appraisal, and overjet at LT. No significant difference between the two groups was found for the changes occurring from PT to LT.

Conclusions: Favorable dentoskeletal outcomes induced by MCH and fixed appliances remained stable in the long term; untreated Class III malocclusion did not show any tendency toward self-improvement during the postpubertal interval.